None of them was the feature you were looking at. Each one was verified on your own code, not guessed from the description.
The frontend could not be installed at all
One package in it does not exist in the npm registry, and it pulls a second package that does not exist either. The install stops with an error before a single line of your code runs. It was also unused: only one animation class from it appears anywhere in the project, and that one is built into Tailwind.
Every page answered with a 500
The frontend had only one of the two Clerk keys in its settings, so the middleware threw on every request. Measured both ways: without the second key every page returns 500, with it every page returns 200.
Invoice generation could not work
The key in the archive was dead, and the three model names written into the code are closed to newly issued keys, so a fresh key alone would not have helped. Both had to be handled.
Fixed and running now
Currency comes from your text. "60 eur per hour" produces an invoice in euro, and the same currency appears in the list, in the editor and in the print view. The print view used to fall back to rupees and to render every other currency with a dollar sign.
Tax is no longer invented. "Plus 23% VAT" gives 23, a text that says nothing about tax gives 0. Every invoice used to carry a hardcoded 18 percent.
The app works on a phone. The side menu was drawn on top of every screen and the close button had no effect, so the app could not be used on mobile at all.
Numbers, dates and totals are checked. 12 × 60 plus 3 × 40 plus 90 gives €930, VAT 23% gives €213.90, total €1,143.90. "Due in 21 days" lands on the right date.
The dashboard tells the truth. It showed invented growth figures of 8.5% and 12.2% on an account with no invoices. Removed, and the totals now follow the currency you actually bill in.
The browser console is clean. Every screen used to fire a failing request for a token template that does not exist in your Clerk instance.
Secrets are out of the code. The database password sat inside the source and travelled with the archive. It now lives in configuration, and the project carries an ignore list so keys stop leaving with it.
An invoice produced from one paragraph of plain text: client, three lines of work, VAT and total, in euro.The dashboard after the clean-up: real totals only, in the currency of the invoices.The same app on a phone, where the menu used to cover everything.
What I would finish next
One decision from you on currency. Euro as the default for every invoice, or a picker per invoice as it works today. The dashboard also needs a rule for accounts that bill in two currencies, because right now it adds them into one number.
The business profile flow. Logo, stamp and signature upload work, but an invoice created before the profile is filled keeps an empty header. It should pick your details up on its own.
Statuses and the PDF. Paid, unpaid and overdue are stored but never change by themselves, and the print layout deserves a pass before you send invoices to real clients.
Putting it online properly. New keys, the database in one place, the app under a supervisor that restarts it, on your own domain rather than my server.
What this costs
Same numbers as my bid, nothing added along the way.
Price300 EUR
Time10 days
StartsOn escrow
The work above is already done and running on the link. What comes with the agreement is the fixed project itself: the code, the archive, the deployment and the walkthrough, so you can run and change it without me. I start the day the money sits in the exchange escrow.